To allow more components to be integrated into a semiconductor chip or a semiconductor device package, one approach is the adoption of flip chip structures. For a flip chip structure, a first wafer is flipped and attached onto a second wafer by conductive bumps. Solder is commonly used to assemble a semiconductor device package. The solder, which is disposed on a pad or copper pillar of a first wafer, is reflowed before attaching to another pad or copper pillar of a second wafer. Substrate and components may be subject to warpage during the reflow operation, which may damage a solder joint. Moreover, a hemispherical shaped solder bump (which is formed by the reflow operation) may also contribute to the warpage of the whole semiconductor device package. Such phenomenon can be particularly noticeable at edges of the package, where the warpage is more intense. The warpage may cause the substrate to bow, warp or crack. Accordingly, there is a need to provide an improved semiconductor device package to solve the above problem.